A problem presented to a Public Safety Answering Point (PSAP; sometimes referred to as a Public Safety Answering Position) in handling emergency service calls received via an emergency telephone network may occur when multiple observers report the same incident such as, by way of example and not by way of limitation, immediately after an accident on an interstate or other highway. Numerous drivers passing by the locus of the accident driving in either direction on the interstate (or driving on cross roads intersecting the interstate) may dial 9-1-1 to report the accident. On very busy interstates it is possible that hundreds of cellular 9-1-1 calls may be made to report the same accident. Such a relatively sudden surge in 9-1-1 call volume can swamp a PSAP and occupy all of the call takers at the PSAP, thereby possibly preventing the call takers from responding to an emergency call regarding another emergency that is unrelated to the accident.
Prior art emergency telephone networks include cellular telephone switches connected to a 9-1-1 tandem telephone switch that routed an emergency service call to the correct PSAP based upon approximate location of the calling cellular phone. Prior to presenting the call to the 9-1-1 tandem switch, the cellular telephone switch queried a Mobile Positioning Center (MPC) or Gateway Mobile Location Center (GMLC) to obtain a pseudo telephone number that is selected based on the caller's approximate location. The 9-1-1 tandem switch was programmed to route any calls originating from the pseudo telephone number to a particular emergency service answering position or emergency call taking facility such as, by way of example and not by way of limitation, a Public Safety Answering Point (PSAP; sometimes referred to as a Public Safety Answering Position). In such a prior art system, the 9-1-1 tandem switch is unable to do anything other than route the call to the predetermined PSAP.
It would be useful if a PSAP call taker or operator could designate a geographic incident region substantially surrounding the location of an accident, identify emergency service calls originating within that designated incident region and provide alternate routing for calls originating from the incident region. By way of example and not by way of limitation, a PSAP operator could define a polygon by drawing the polygon on a map presentation. The alternate routing may be previously established to automatically effect routing emergency calls to alternate PSAPs in a previously predetermined priority order.
There is a need for a system and method for effecting alternate routing of emergency service calls originating from a temporarily designated region to divert emergency callers to one or more alternate PSAPs in order to reduce call volume to a single PSAP from a region associated with repeat reports of a single incident, or for another reason.